title: Revisional percutaneous full endoscopic disc surgery for recurrent herniation of previous open lumbar discectomy.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  To determine the feasibility and effectiveness of revisional percutaneous full endoscopic discectomy for recurrent herniation after conventional open disc surgery. OVERVIEW OF THE LITERATURE: Repeated open discectomy with or without fusion has been the most common procedure for recurrent lumbar disc herniation. Percutaneous endoscopic lumbar discectomy for recurrent herniation has been thought of as an impossible procedure. Despite good results with open revisional surgery, major problems may be caused by injuries to the posterior stabilized structures. Our team did revisional full endoscopic lumbar disc surgery on the basis of our experience doing primary full endoscopic disc surgery.
  
  
  METHODS
  Between February 2004 and August 2009 a total of 41 patients in our hospital underwent revisional percutaneous endoscopic lumbar discectomy using a YESS endoscopic system and a micro-osteotome (designed by the authors). Indications for surgery were recurrent disc herniation following conventional open discectomy; with compression of the nerve root revealed by Gadolinium-enhanced magnetic resonance imaging; corresponding radiating pain which was not alleviated after conservative management over 6 weeks. Patients with severe neurologic deficits and isolated back pain were excluded.
  
  
  RESULTS
  The mean follow-up period was 16 months (range, 13 to 42 months). The visual analog scale for pain in the leg and back showed significant post-treatment improvement (p < 0.001). Based on a modified version of MacNab's criteria, 90.2% showed excellent or good outcomes. There was no measurable blood loss. There were two cases of recurrence of and four cases with complications.
  
  
  CONCLUSIONS
  Percutaneous full-endoscopic revisional disc surgery without additional structural damage is feasible and effective in terms of there being less chance of fusion and bleeding. This technique can be an alternative to conventional repeated discectomy.
authors.affiliation: Department of Orthopaedic Surgery, Shin Hospital, Suwon, Korea.
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Shin
authors.forename: Ho-Guen
authors.initials: HG
authors.lastname: Chang
authors.forename: Nam Kyou
authors.initials: NK
authors.lastname: Rhee
authors.forename: Kwahn Sue
authors.initials: KS
authors.lastname: Lim